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Post by rcq92130 on Oct 28, 2014 18:52:16 GMT -5
1. It really is 60mm. I'll be happy to measure for you on Thursday when it arrives (just shipped today). 2. No valve/piston slapping. Both valves and piston are pretty dirty (soot), but not marks. 3. Good point about valve size. never even thought about that.   |
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Post by rcq92130 on Oct 28, 2014 13:38:12 GMT -5
In trying to figure out why this BBK failed so fast, I wondering if i installed the piston "upside down", causing it to wobble and damage the liner. Here is a photo of the piston i used. On the top it has the size ("60") stamped and an arrow pointing to one of the valve idnents. I htought the arrow should be pointing to the INTAKE side, and installed it with the arrow facing "up". Maybe that's wrong. Anyone know???  |
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Post by rcq92130 on Oct 27, 2014 20:25:22 GMT -5
Yeah, what I ordered is a new jug, piston, rings, gudgeon pin. Whole thing (from Taiwan) is only $70, so it didn't make sense to see if new rings would solve it, or if maybe the liner was gouged, etc
RE: break in: Most seem to think the main commandment is to vary throttle at first. So wen the current (now gone bad) BBK was first in I spent a while going up and down local hills, over and over .... till I became worried someone would call the locals on me. Still something went bad obviously.
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Post by rcq92130 on Oct 27, 2014 20:21:24 GMT -5
HBob -
About that catch can.
My first thought was to put in a crankcase vent (in the dipstick hole) leading to a can that would let the oil go back into the case at night/when off. But that was treating the symptom, not the problem. Expect the new piston liner/piston/rings will greatly reduce or nearly eliminate blowby, but still a can might make sense.
My question is, though : what about venting the can back into the intake manifold? I have only one nipple there, but am not using it since I have an electric pump and a pumper carb (so no vacuum lines needed). Another thought is to add a nipple to the intake duct (upstream of the carb) to preserve fuel/gas mixture ... but then any oil in the fumes might gunk up the carb butterfly, etc.
Your thoughts?
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Post by rcq92130 on Oct 27, 2014 16:15:08 GMT -5
Well, kind of have an answer.
Did another compression test - this time squirting a little oil in first. Gained 30 to 40 psi.
So, ordered another jug & piston - not knowing if it's the rings or the cylinder walls, and not willing to tear the thing down just to find out.
Two or three days and then back at the thing. Getting repetitive! Worst thing is I'll have to go thru break in AGAIN! Argggggggggggggggg !!!!!!!!!!!
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Post by rcq92130 on Oct 27, 2014 13:15:40 GMT -5
No, I did NOT wipe down the jug before installing it. Checked compression yesterday --- 135 is not fabulous for a new piston/jug/head assembly, but not out of the norm either (and my reading might be low since i don't have a tester that will screw into the small plug hole - had to use the one with a rubber bulb on the end that you just push against the spark plug hole .... with of course chance for leakage).
Will change the oil and see if there is any water in it. Time to switch over to synthetic anyway ...
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Post by rcq92130 on Oct 27, 2014 7:53:39 GMT -5
Hi John
Thing is - zero miles on new head with new valves, springs, etc.
Also - nothing at all odd in exhaust out the end of the muffler (no smoke, etc.). Wouldn't I see something if it was rings?
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Post by rcq92130 on Oct 26, 2014 21:58:55 GMT -5
Far as I know, your gas tank is under the floor (like mine), and the OEM location of the vacuum pump is half way up towards the carb. That may be part of the issue with a vacuum pump - too high above the tank. It also made first start REALLY difficult, waiting for the pump to fill the fuel bowl of the carb.
I have ZERO worry about the pump delivering enough fuel for this little motor. Rather, I am worried about the pressure being too high and overpowering the needle valve (forcing too much fuel into the bowl). Might try a regulator at some point ... but will first wait to see if the new pump (with a lower set point on pressure) seems more agreeable.
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Post by rcq92130 on Oct 26, 2014 20:03:43 GMT -5
The emissions system on this 150 GY6 vanished. Now, the vent off the valve cover is a hose that goes back & up to the high point under the seat, then down to above the muffler, then back up & toward the front where there is a fuel filter that is open to air.
Didn't notice it before, but there is a LOT of smoke coming out in a constant stream from the fuel filter --- and splatterings of oil (and WATER, I think !!!). Maybe this was there all along and I just didn't notice ... but it seems very, very "not normal". Scooter seems to be running very well otherwise ...
Brand new cylinder head, so not likely there is valve leakage. Maybe rings? Only 400 miles on the BBK jug, and did a semi-easy break-in. But maybe rings failed anyway.
Any thoughts anyone?
Video of smoke:
Video of splatterings:
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Post by rcq92130 on Oct 24, 2014 22:52:26 GMT -5
There is no way JB Weld would last for any length of time right at the exhaust port of the cylinder head.
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Post by rcq92130 on Oct 24, 2014 21:31:30 GMT -5
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Post by rcq92130 on Oct 24, 2014 12:54:15 GMT -5
Just did that.
Pump I got seems to work OK - but mine is rated at 5 to 8 psi, which is on high for the little needle valves in these things. Have ordered another at 2 to 4 psi, more sensible. Either one is about $20 delivered.
Hook it up with a relay energized by something that gets +12V when ignition is "On" - not directly from the ignition source.
Downside: My ammeter used to hover around 14v when riding, now down to 12v. Current drain MAY (?) be a bit much for the teensy stators on these things. Not sure yet.
As for "scooter's" comment:
My vacuum operated P.O.S. pump failed after 3 months. THAT is a source of failure. In fact - the entire notion of bleeding off manifold vacuum seems stupid to me, as is the idea these vacuum pumps will necessarily do all that is needed, reliably, at WOT. Electric is fine in those situations, and - if you ever have to empty the carb bowl of fuel, you will not be cranking for a day to get the engine to first start.
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Post by rcq92130 on Oct 20, 2014 13:34:49 GMT -5
Vice grip attached IN THE MIDDLE (where there are no threads). Spray with some penetrating oil first just in case.
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Post by rcq92130 on Oct 15, 2014 18:35:13 GMT -5
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Post by rcq92130 on Oct 14, 2014 21:50:49 GMT -5
Battery dead.
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